So few service members were testing positive for LSD in recent years that the man-made hallucinogen was dropped from standard urinalysis screenings, according to the Pentagon's head of militarywide drug testing.

"It's a business-practice decision," said Col. Ronald Shippee, director of the Defense Department's drug testing and program policy office. "I don't have unlimited resources to run these labs."

In a recent interview, Shippee said the military's six drug-screening labs nationwide test some 4 million samples every year for illegal drug use. For standard screenings, the labs test for cocaine, heroin, marijuana, amphetamines and methylenedioxymethamphetamine - commonly known as MDMA or Ecstasy. Other drugs can be added in random "pulse" tests or requested specifically by a command.

LSD "had been part of the standard panel under the 'pulse' category," Shippee said. "That's why, in the last three years, we did about 12 million specimens, but probably only 2 million were screened for LSD."

With the increasing prevalence of other drugs susceptible to abuse, such as the prescription pain medication Oxycodone, the cost of testing for LSD could not be justified by the low positive results.

"When we say we 'drop a drug' we don't drop it off the radar," he said. "So, if you've got a drug like LSD which we saw...four positives in three years, that's a lot of expense and a lot of work for nothing. So we drop it from the panel."

Shippee also noted that testing for the hallucinogen presents a "technical nightmare" to screeners. Due to its man-made, chemical nature, LSD leaves the body quickly, unlike cocaine or marijuana.

Shippee works closely with the various criminal investigation agencies in the military, which often provide advance insight into looming problems. In the mid-1990s, for example, investigators were reporting on increasing use of a new party drug now known as Ecstasy.

Shippee said the military was far ahead of the public on that one. "When the big peak hit the country in 2000, we were already looking at it," he said.

Lately, a blend of Ecstasy laced with crystal meth, a highly addictive street drug, has made a comeback. It was announced as a new Canadian import by the Office of National Drug Control Policy. A policy board that examines drug testing may decide to sample drug screens for its prevalence.

"There's no screen, so we're thinking of taking a look and seeing what's in the population," Shippee said. "When we find it that way, we don't use it to discipline anybody. We just use it to set policy."

Another relatively new adjustment is testing for Oxycodone, known by the brand name Oxy-Contine. Shippee said it was added to screenings in August 2005 after being detected in random testing.

"We took a look at four or five of the labs over a four-month period and saw what we considered a significant amount," he said.

Shippee's forensic pathologists are often called to testify at courts-martial. He said some drug use by service members reveals a full spectrum of abuse.

"You'd be amazed. I could show you urine that has Ecstasy, methamphetamine, cocaine and marijuana," he said. "We hear it all in court. It all comes out."

Overall statistics for drug testing in the military are not readily available, but soon will be. Shippee said he is in the process of placing a vast accumulation of testing data on the Internet for public access.

"We're not hiding anything," he said.